Menu
I need to sort an array of ints using a custom comparator, but Java's library doesn't provide a sort function for ints with comparators (comparators can be used only with objects). Is there any easy way to do this?
601
int[][] twoDim = { { 1, 2 }, { 3, 7 }, { 8, 9 }, { 4, 2 }, { 5, 3 } }; Arrays. sort(twoDim, (int[] o1, int[] o2) -> o2[0] - o1[0]); System. out. println(Arrays.
Using a comparator, we can sort the elements based on data members. For instance, it may be on roll no, name, age, or anything else. Method of Collections class for sorting List elements is used to sort the elements of List by the given comparator.
If you can't change the type of your input array the following will work:
final int[] data = new int[] { 5, 4, 2, 1, 3 }; final Integer[] sorted = ArrayUtils.toObject(data); Arrays.sort(sorted, new Comparator<Integer>() { public int compare(Integer o1, Integer o2) { // Intentional: Reverse order for this demo return o2.compareTo(o1); } }); System.arraycopy(ArrayUtils.toPrimitive(sorted), 0, data, 0, sorted.length); This uses ArrayUtils from the commons-lang project to easily convert between int[] and Integer[], creates a copy of the array, does the sort, and then copies the sorted data over the original.
119
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
